Tag: Permanent wildflower margins and corners

Why is farmland important for this species?

Hedgehogs are found throughout the UK in all habitats. They have historically been associated with farmland for centuries. Hedgehogs are insectivores, foraging in fields and on grassland for worms, and along field margins and at the base of hedgerows for beetles, snails and other invertebrates. They are considered a generalist species, inhabiting most areas of our countryside, our villages and many areas of our towns too. However, as the dominant habitat in the UK, farmland is particularly important for hedgehogs.

Hedgehog (c) Stephen Oliver

Hedgehogs, like all animals, need to feed, hide from predators and find mates. A variety of habitats that provide foraging areas and secure nesting sites is ideal. Both arable and pasture land can support healthy hedgehog populations. Wide, species-rich hedgerows with buffers of grassy margins on either side provide safe ‘highways’ for hedgehogs to move around the landscape. Hedgerows with wide bases that are managed on rotation should have healthy invertebrate populations for hedgehogs to feed on. Old hedges with dense root systems and lots of deciduous leaves are ideal for them to use as nesting sites, both during the summer and in winter as hibernation spots.

The denser the network of hedges, the more securely hedgehogs can move around, and the higher the availability of prey species for them to feed on.

Recently ploughed fields can provide a bounty of earthworms and other prey; hedgehogs can be found in-field taking the opportunity to feed on invertebrates once crops have been harvested.

Recent studies show hedgehogs are found nearer to farm buildings. These areas could be providing safety from predators on farmland with less robust and fewer hedgerows, and larger fields.

Habitat management

Hedgerows:

Increasing hedgerow availability provides more nesting and foraging areas for hedgehogs. Ensure that hedgerows are species-rich, contain native trees and are as wide, high and dense as possible. Maintaining hedge bases at least 2m wide with minimal or no gaps provides secure safe nesting sites. Managing hedgerows on a 3 year rotation ensures that hedges remain diverse and robust.

Smaller field sizes with a mixed crop provides greater variety, and therefore greater food security, for hedgehogs and other wildlife. Increasing hedges and field margins on farms with fewer, larger fields, provides habitat for hedgehogs. Reducing tillage or moving to no-till or conservation agriculture reduces soil compaction, increases soil invertebrates and improves and increases the depth and quality of the soil organic layer.

Pesticide & herbicide use:

Reducing pesticide and herbicide use means that more invertebrate prey, in particular earthworms, will be available on farmland for hedgehogs to feed on.

The above management measures recommended to provide a healthy landscape for hedgehogs are typically those associated with traditional farming practices. There should be no problems, though many of the measures may be more time-consuming than those associated with farming on a larger scale.

Hedgerow with grassy margin (c) Gethin Davies

Peoples Trust for Endangered Species (PTES) and British Hedgehog Preservation Society (BHPS) have created an advice note detailing management and stewardship options that will benefit not only hedgehogs but other wildlife too (see link below).

Benefits and costs

Creating and managing hedgerows sensitively has financial costs but there are stewardship options available; individual ones for the management regimes listed above are detailed in the attached advice note.

Hedgehog (c) Ben Andrew (rspb-images.com)

Managing a farm for a species such as a hedgehog involves looking at the farm as a whole. Unlike species that fly, such as butterflies, hedgehogs needs the entire landscape to be suitable in order to thrive. Consequently, many of the management techniques recommended to improve habitats for hedgehogs will also provide a healthier landscape. A denser proportion of hedges and associated smaller field sizes both help to reduce soil erosion. Reducing tillage improves soil organic matter and reduces soil compaction.

Aims:

The aim was to create an insect-rich foraging habitat for farmland birds. I farm on fertile peat soils, so effective control of pernicious weeds is essential.

Management:

I started using this option 5 years ago. For the first four years, I cultivated annually in the spring. Blackgrass is hit by spring cultivations and the seed is short-lived, so successive spring cultivations along with lack of fertiliser have virtually eliminated it.

This year, I applied a herbicide in March to control grass weeds instead of cultivating. This has the advantages of providing seed food for birds through the ‘hungry gap’ (January – April inclusive), providing pollen and nectar throughout the spring, and I think that the plant diversity has increased as a result. It has taken me 4 or 5 years to get the margins to produce food in the lean time of year, because of the need for annual spring cultivations to get on top of the blackgrass. If someone has no blackgrass then an early spring food source can be produced in year two or three. In future, I may only cultivate in alternate years and use herbicide in the 2nd year.

Creeping thistle is a major concern with potatoes and sugar beet in the rotation, so I spot spray thistles with a knapsack sprayer. This has reduced the thistle numbers over time. I had to spot-spray some areas to remove couch and field bindweed with a boom sprayer at harvest time, when the annuals were dormant.

Achievements:

The floristic diversity of these margins is unparalleled by any other habitat on the farm. Plant species richness per margin varies from 55 to 70 species, almost an order of magnitude greater than my wild flower margins, and even more impressive compared with my grass margins, ditch banks and hedgerows.

In years when the spring cultivation is not required, it delivers pollen and nectar throughout the year as well as any sown mixture. Red dead-nettle feeds bumblebees in March and a progression of a wide range of flowers take over from then onwards. When spring cultivation is undertaken, these margins provide pollen and nectar from June onwards.

The full range of farmland birds forage for insects in these margins: grey partridges, linnets, reed buntings, corn buntings and even quail. Turtle doves are scarce on the farm now: common sense suggests that they should use them as a source of seed food too, but I have not been able to witness this. I now have ten times the density of linnets feeding on this farm compared with neighbouring farms. I put this down to the availability of seeds in these margins. I think that the accessibility to the ground in combination with the abundance of insects (and seeds in the case of linnets) provides the ideal conditions for foraging birds.

The combination of spring cultivations, use of selective herbicide and spot-spraying have effectively controlled all of the noxious weed problems. Uncropped cultivated margins are more work than grass margins, but less than some of the other arable options, such as wild bird seed mixtures.

Aims:

The aim was to boost insect food for farmland birds through the summer. The farm is on peat soils in the Lincolnshire Fens.

Management:

The first margins were established 15 years ago. A wild flower and grass mix was purchased from Emorsgate Seeds. The seed mixture was 20% wild flowers and 80% fine grasses. Wildflowers included yarrow, common knapweed, wild carrot, lady’s bedstraw, self-heal, meadow buttercup, common sorrel and red campion. In addition, some flowering plants that were not in the original seed mix have established from the seed bank.

We cut them for hay in early August, as we have a market for it. Cutting and removing is important to reduce the fertility and maintain the floristic diversity. In addition, I have applied a herbicide in the spring whenever I have considered that coarse grasses were becoming a problem in the previous summer. One margin was sprayed this year for the first time in 7 years. I also pull ragwort and spot-spray thistles with a knapsack sprayer.

Achievements:

Although the floristic diversity of the original mix has declined, they remain as diverse flower margins absolutely humming with insect life. Knapweed has not survived in some of the mixtures on the acid soils. Our 15-year-old margin still retains mallow, sorrel, wild carrot, buttercup, lady’s bedstraw and self-heal. Yarrow has remained particularly dominant. In one margin, we incorporated cowslip and betony, but these did not appear in the sward until 5 years and 8 years after sowing, respectively.

The range of birds that use them has disappointed me. They are used by skylarks, meadow pipits and linnets (which take the sorrel seeds), but apparently not by my corn buntings and other small passerines. It may be that they are too dense for them. As a result, I have tried uncropped cultivated margins as an alternative means of providing an insect-rich foraging habitat for birds.

I feel that they are a significantly better option for wildlife than the standard grass margins.